In the field of communications technologies, a protocol packet of a Slow Protocol has the following characteristics. A destination Media Access Control (MAC) address of the protocol packet uses a Slow_Protocols_Multicast address, and a value of the Slow_Protocols_Multicast address is 01-80-c2-00-00-02, and a value of a type field of the protocol packet is 8809.
Currently, a local device usually establishes a communications link to a peer device in a negotiation process based on the Slow Protocol. To maintain the communications link, the local device and the peer device send the protocol packet to each other in a working process after the negotiation process. After receiving the protocol packet, the local device or the peer device triggers a corresponding operation based on link information indicated in the protocol packet, for example, triggers a fault processing operation based on link fault information.
However, a security threat exists in the working process. When the local device and the peer device are in the working process, an attacker may control either the local device or the peer device to construct a protocol packet, and instruct the device receiving the protocol packet to execute an incorrect action, for example to trigger link fault handling when the communications link is normal. It can be learned that how to resolve the security threat to improve security is a technical problem needing to be resolved currently and urgently.